Strain yields over 100-fold resistance response in magic-angle graphene

This control addressed a persistent practical problem. Researchers can rarely place two microscopic flakes directly atop one another without accidentally stretching or warping one or both. Those distortions create a messier, more complicated moiré pattern. Yankowitz described the alignment challenge as trying to lay two massive sheets of shrink wrap perfectly flat without wrinkles.

Yankowitz and Chu asked whether controlling that stretch would reveal new properties. The result was striking: adjusting strain produced a resistance change more than 100 times the change in an ordinary metal. Cooling amplified the response further, giving the team a pronounced electrical signal with which to probe the material.

Yankowitz, a UW associate professor of physics and materials science and engineering, said: “Atomically thin materials can host superconductivity, magnetism and other exotic quantum states. We've now added a fundamentally new way to manipulate them, by directly deforming the atomic lattice they live on. That enables experiments we simply couldn't do before.”

Takeaway: Voltage-driven stretching now gives researchers a direct, continuous knob for changing the atomic geometry of magic-angle graphene.

What can strain reveal?

Before this work, researchers could already use voltage, magnetic fields and temperature as control knobs. They could move a sample in predictable, repeatable sequences—from metal to insulator, back to metal, then to insulator and superconductor—so one device could represent a family of materials and show how superconductivity relates to neighboring states.

An insulator resists electric current; a superconductor allows it to flow without resistance.

Strain adds a control that acts directly on the lattice. The giant response gives researchers another way to probe and control different electronic states without relying only on temperature or magnetic fields. It also connects a familiar mechanical action—pushing or pulling—to measurable changes in current flow.

The study demonstrates the control in magic-angle twisted bilayer graphene. It does not provide a complete microscopic explanation for why the response becomes so large, and researchers have yet to show that the same device approach works in the other atomically thin materials they want to test.

Takeaway: The advance expands the experimental toolbox, but the microscopic reason for the giant response remains a research question.

Why does the result matter?

Yankowitz and Chu plan to simplify the apparatus so other laboratories can reproduce it more readily. They then want to apply strain control to other atomically thin materials. Their broader aim is to extract more knowledge from each sample and better understand the hidden behaviors that govern matter, with possible relevance to another computing revolution.

Chu connected the result to a larger open problem: “What is remarkable about this giant response to strain is that it also appears in other exotic materials, including high-temperature superconductors, one of the great unsolved problems in physics. This common link brings us a step closer to understanding what underlies these fascinating and complex phenomena.”

The study appears as “Giant elastoresistance in magic-angle twisted bilayer graphene,” by Xuetao Ma and colleagues in Science. The citation lists the journal year as 2026, and the DOI is 10.1126/science.adz0597.

Takeaway: Strain control may become a practical route into both new quantum experiments and a deeper account of superconductivity.